MOLECULAR GAS IN z ∼ 6 QUASAR HOST GALAXIES

By Ran Wang, C. Carilli, R. Neri, D. Riechers, J. Wagg, F. Walter, F. Bertoldi, K. Menten, A. Omont, P. Cox and 1 more. 2010

159 citations recorded by the source corpus.

We report our new observations of redshifted carbon monoxide emission from six z ∼ 6 quasars, using the IRAM Plateau de Bure Interferometer. CO (6–5) or (5–4) line emission was detected in all six sources. Together with two other previous CO detections, these observations provide unique constraints on the molecular gas emission properties in these quasar systems close to the end of the cosmic re-ionization. Complementary results are also presented for low-J CO lines observed at the Green Bank Telescope and the Very Large Array, and dust continuum from five of these sources with the SHARC-II bolometer camera at the Caltech Submillimeter Observatory. We then present a study of the molecular gas properties in our combined sample of eight CO-detected quasars at z ∼ 6. The detections of high-order CO line emission in these objects indicates the presence of highly excited molecular gas, with estimated masses on the order of 1010 M☉ within the quasar host galaxies. No significant difference is found in the gas mass and CO line width distributions between our z ∼ 6 quasars and samples of CO-detected 1.4 ⩽ z ⩽ 5 quasars and submillimeter galaxies. Most of the CO-detected quasars at z ∼ 6 follow the far-infrared–CO luminosity relationship defined by actively star-forming galaxies at low and high redshifts. This suggests that ongoing star formation in their hosts contributes significantly to the dust heating at FIR wavelengths. The result is consistent with the picture of galaxy formation co-eval with supermassive black hole (SMBH) accretion in the earliest quasar–host systems. We investigate the black hole–bulge relationships of our quasar sample, using the CO dynamics as a tracer for the dynamical mass of the quasar host. The median estimated black hole–bulge mass ratio is about 15 times higher than the present-day value of ∼0.0014. This places important constraints on the formation and evolution of the most massive SMBH-spheroidal host systems at the highest redshift.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/314cd53c0277d584adef704e68d4ab052df2e418

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In Astronomy and Astrophysics

1. L. Hernquist
2. F. Walter
3. C. Carilli
4. P. Hopkins
5. D. Narayanan
6. Xiaohui Fan
7. S. Furlanetto
8. M. McQuinn

Citations in the corpus

• Cool Gas in High-Redshift Galaxies (2013, background): “Wang et al. (2010) present the most detailed analysis to date out to z ∼ 6.”
• An ALMA [C ii] Survey of 27 Quasars at z > 5.94 (2018, background): “…immense (a few times 1010 M ) reservoirs of molecular gas, which can be detected through the rotational transitions of the carbon monoxide (CO) molecule (e.g., Carilli et al. 2002; Bertoldi et al. 2003b; Walter et al. 2003, 2004; Riechers et al. 2006, 2009; Wang et al. 2010; Venemans et al. 2017b).”
• THE PAN-STARRS1 DISTANT z > 5.6 QUASAR SURVEY: MORE THAN 100 QUASARS WITHIN THE FIRST GYR OF THE UNIVERSE (2016, methodology): “Ideally, we would prefer to measure the redshifts from atomic or molecular emission lines such as [C II] and CO, which provide host galaxy redshifts as accurate as ∆ z < 0.002 (e.g., Wang et al. 2010; Bañados et al. 2015a).”
• STAR FORMATION AND GAS KINEMATICS OF QUASAR HOST GALAXIES AT z ∼ 6: NEW INSIGHTS FROM ALMA (2013, methodology): “…found with other high-z FIR and CO luminous quasars that the SMBH–bulge mass ratios are 10–30 times higher than the average value of 0.0014 found in local normal galaxies (Marconi et al. 2003; Walter et al. 2004; Riechers et al. 2008; Wang et al. 2010; Coppin et al. 2008; Venemans et al. 2012).”
• The MassiveBlack-II simulation: The evolution of haloes and galaxies to z ~ 0 (2014, unknown): “Wang et al. 2010, 2011).”
• EDDINGTON-LIMITED ACCRETION AND THE BLACK HOLE MASS FUNCTION AT REDSHIFT 6 (2010, background): “Note that our results are not necessarily in conflict with the molecular gas observations of z ∼ 6 quasars that show they have high ratios of MBH to Mbulge (Walter et al. 2004; Riechers et al. 2008; Wang et al. 2010).”
• DETECTION OF ATOMIC CARBON [C ii] 158 μm AND DUST EMISSION FROM A z = 7.1 QUASAR HOST GALAXY (2012, background): “The CO lines observed in z ∼ 6 quasars have line FWHMs between 160 and 860km s−1, with a median around 350 kms−1 (e.g. Wang et al. 2010, 2011).”
• INTENSITY MAPPING WITH CARBON MONOXIDE EMISSION LINES AND THE REDSHIFTED 21 cm LINE (2011, methodology): “Wang et al. (2010) fit a correlation between far-infrared luminosity and CO luminosity using measurements from galaxies at z = 0 − 3, including spiral galaxies, LIRGs, ULIRGs, and SMGs. Specifically they fit a power law relation between far-infrared luminosity and the velocity integrated CO(1-0)…”
• BLACK HOLE MASS ESTIMATES AND EMISSION-LINE PROPERTIES OF A SAMPLE OF REDSHIFT z > 6.5 QUASARS (2013, background): “For high-redshift quasars, it is possible to obtain a direct estimate of the systemic redshift through the detection of cold molecular gas phase in the host galaxy (e.g., Walter et al. 2003; Wang et al. 2010; Venemans et al. 2012).”
• Production of dust by massive stars at high redshift (2011, background): “For bright high-zobjects, FIR luminosities of the order of 1012−13 L⊙ are usually derived (e.g., Omont et al, 2001; Bertoldi and Cox, 2002; De Breuck et al, 2003; Robson etal, 2004; Beelen et al, 2006; Wang et al, 2010; Ivison et al, 2010; Leipski et al, 2010).”